Mini review I wrote on another forum:
I was recently able to get my hands on a CKM99 (left) and a CKM55 (right), and decided to make a full blown review because of how different they sounded from one another. AFAIK, The CKM99 is currently the top of the line dynamic offer from Audio Technica.
Construction: The shell of the CKM55 is made of plastic, while that of the CKM99 is made of titanium. The front portion of both earbuds are virtually the same; made of plastic and stuck to the back portion using adhesive. The shell of the CKM99 is noticeably bigger and heavier. The biggest difference for me however lies with the cables. The CKM99's cables are comparatively much thicker and have a longer and thicker strain relief as well. This isn't a small matter when dealing with non-detachable cable type IEMs.
In terms of fit, the ckm55 is more comfortable because it's quite a bit lighter, and the metal of the ckm99 tends to feel uncomortably cold when first put on. The shorter housing length of the ckm55 also helps a lot with getting a comfortable fit initially. Both are shallow insertion IEMs with angled nozzles, but they somehow manage to be comfortable because of their rounded shape.
Sound Quality
CKM55: It has a foward midrange that seems overly focused on making itself heard over the highs and lows. While there's no lack of clarity in the mids, the treble seems to recessed and the bass is drowned out by the mids at times. Its's quite noticeable on tracks with quick bass beats like in house music and hip-hop. The bass of the CKM55 seems like a "one note bass", meaning it has copious amount of midbass but it doesn't go very deep. The CKM99 is the same in the sense that it lacks or is incapable of producing sub bass, except it has more impact, which only serves to further emphasize the deficiencies in bass detail. Take note that I'm comparing the bass to a Denon D5000, which is quite well known for having very good detail on bass. Compared to other IEMs, both do rather well for their price range.
Compared to the similarly priced Dunu Trident, the ckm55 has a less grainy sound, although it's less neutral as well. The Trident also has slightly wider soundstage, hence more accurate instrument placement, probably due to where the vents are located. Both of them have treble that rolls off a little too early, and in terms of bass both could use a little more impact.
CKM99: The ckm99 is a bright iem with a V-shaped frequency response, similar to dual BA iems like the B2 and DBA02 or headphones like the DT990. Given these characteristics, the ckm99 can be siblant and sounds like it has a recessed midrange on a lot of pop music with emphasized bass. The ckm99 has an upper midrange emphasis like a lot of other ATH products, and sounds excellent with acoustic instruments and generally anything that it doesn't sound siblant with, which is unfortunately not a lot of songs.
Listening comparisons:
The Smiths – There Is A Light That never Goes Out
CKM99: No siblance, Accurate reproduction, not sibilant, nails the bass guitar which holds the entire song together
CKM55: Bass sounds deficient, mids are too forward and
make other instruments like guitars and drums much less noticable
George Strait – Heartland
CKM99: Siblant, good imaging with very clear distinction for instrument placement, was not a pleasurable listen because of the siblance
CKM55: Soundstage sounds closed in, forward mids, treble seems to be recessed, no siblance detected
Pitbull – Give Me Everything Tonight
CKM99: No siblance, impactful bass, never turns siblant
CKM55: Bass is a little lacking, forward mids seem too forward as I don’t really want to hear Pitbull sing and not much else, especially in a dance song
Jane Monheit – I Wish You Love
CKM99: Excellent presentation of vocals, bass a little too prominenet, good extension on treble, imaging is accurate
CKM55: More forward mids with slight loss in clarity, smaller soundstage, just the right amount of bass and less sparkle on treble
Summary: Both are solid competitors within their respective price ranges, at least for the price I got them at ($28 for CKM55, $109 for CKM99). Get the CKM55 if you're looking for a neutral but mid-centric shallow insert IEM that doesn't lack bass (most of the time), although it can sound a little constrained at times. Get the CKM99 if you like dynamic driver IEMs with lots of bass and treble sparkle with great vocal presentation, although the highs can get shrill and siblance is a pretty big issue.
